1. Field of the Invention
The present invention relates to a battery pack incorporating an induction coil electromagnetically coupled to a primary coil in a battery charger cradle so as to recharge a battery by means of the induction coil, and particularly relates to a battery pack which is placed, instead of a size AA battery, in a battery storage of an electronic device having been designed to load a plurality of size AA batteries in a mutually parallel relationship.
2. Description of the Related Art
There has been developed a structure for a battery to be recharged by electric power being carried from a primary coil to an induction coil (a secondary coil) by the effect of electromagnetic induction. Refer to Japanese Patent Laid-Open Publication No. H09-63655 (1997) and Japanese Utility Model Registration No. U-3011829.
Described in Japanese Patent Laid-Open Publication No. H09-63655 (1997) is a structure in which the primary coil excited by a high-frequency power source is incorporated in a battery charger cradle and the induction coil electromagnetically coupled to the primary coil is incorporated in a battery pack. The battery pack also incorporates a circuit in which an alternating current induced in the induction coil is rectified and such rectified current is supplied to a battery to be recharged. In accordance with such structure, the battery pack is placed on the battery charger cradle so that the battery contained in the battery pack can be recharged in a non-contact state.
Also described in Japanese Utility Model Registration No. U-3011829 is a structure in which the battery is contained in the bottom of mobile electronic equipment and a secondary-side charging adaptor is provided subjacently to the battery so that the induction coil and charging circuit are incorporated in the secondary-side charging adaptor. Also described is a structure in which the primary coil electromagnetically coupled to the induction coil is provided to the battery charger cradle. The mobile electronic equipment coupled to the secondary-side charging adaptor is placed on the battery charger cradle, and the electric power is carried from the primary coil to the induction coil to recharge the battery contained in the mobile electronic equipment.